Heavy metal removal methods and systems

Abstract

A support impregnated with selenium and capable of effectively removing a heavy metal from a process stream that is at an ambient temperature or is at an elevated temperature.

1 . A system comprising:
 a porous activated carbon support impregnated with selenium at a temperature of 650 degrees Celsius in a vacuum chamber, wherein the porous activated carbon support is made of a substrate made porous; and   a liquid process stream at about 100 degrees Celsius in fluid communication with the support, wherein the process stream contains mercury for removal using the porous activated carbon support.   
     
     
         2 - 3 . (canceled) 
     
     
         4 . The system of  claim 1 , wherein the selenium is elemental selenium. 
     
     
         5 . (canceled) 
     
     
         6 . The system of  claim 1 , wherein the impregnated support has 6.5 wt. % or greater selenium. 
     
     
         7 . (canceled) 
     
     
         8 . The system of  claim 1 , wherein the porous support is an inorganic material other than activated carbon. 
     
     
         9 . The system of  claim 1 , wherein the porous support is shaped into particles or pellets about 10 mm in length or less. 
     
     
         10 . A support comprising:
 an activated carbon substrate impregnated in a vacuum with selenium at 650 degrees Celsius to provide the support that is at a temperature greater than 100° C. and is suitable for use in removal of mercury from a liquid process stream, wherein the substrate is activated to become porous before being impregnated.   
     
     
         11 . (canceled) 
     
     
         12 . The support of  claim 10 , wherein the selenium is elemental selenium. 
     
     
         13 . (canceled) 
     
     
         14 . The support of  claim 10 , wherein the impregnated substrate has 6.5 wt. % or greater selenium. 
     
     
         15 . (canceled) 
     
     
         16 . A method comprising:
 preparing a porous support, wherein a substrate for the porous support is activated to become porous;   impregnating the porous support with selenium at 650 degrees Celsius in a vacuum environment to create an impregnated porous support;   preparing a bed of the impregnated porous support;   running a liquid process stream through the bed with the temperature of the porous support at about 100 degrees Celsius;   removing mercury from the liquid process stream by sorbing mercury on the porous support, which is at a temperature of about 100 degrees Celsius;   removing the porous support from the liquid process stream;   regenerating the porous support by heating the porous support to above 150 degrees Celsius thereby desorbing the mercury from the porous support.   
     
     
         17 . The method of  claim 16 , wherein the step of impregnating the porous support occurs for at least about  120  minutes. 
     
     
         18 . The method of  claim 16 , wherein the step of impregnating the porous support includes placing the porous support with selenium in an inert environment. 
     
     
         19 - 20 . (canceled)